The present invention relates to a thin-film magnetic head for recording data and/or reproducing the data in a magnetic medium such as a hard disk or a floppy drive, and to a method of manufacturing the thin-film magnetic head.
Very narrow width recording and reproducing data to and from magnetic media is more and more progressing in accordance with the recent requirements of high density recording of storage devices, and sub-micron width of magnetic writing track is needed to satisfy the recording density equal to or more than 10 Gbpi.
In order to realize such very narrow width writing and reproducing, a magnetic head with a magnetic gap that tilts against the direction of the writing track width, such as an azimuth-angled magnetic head usually used in VTR is well known.
Japanese Patent Unexamined Publication No.06-333210 discloses a thin-film magnetic head in which a magnetic layer is partially etched away to form a tilted area and then a writing gap is formed along the tilted area.
Japanese Patent Unexamined Publication No.03-063912 discloses a thin-film magnetic head in which a first magnetic layer is partially removed to form a tilted area by mechanical processing, ion milling or etching, then a writing gap and a second magnetic layer are stacked, and after that a magnetoresistive effect (MR) sensor element is formed in the middle of a yoke constituted by the first and second magnetic layers.
Japanese Patent Unexamined Publication No.09-305905 discloses a thin-film magnetic head in which a pair of yokes are formed so as to oppose with each other via an azimuth angled magnetic gap, and then a MR sensor element is formed between the yokes.
In case of Japanese Patent Unexamined Publication No.06-333210, however, both data recording and reproducing are done by inductive coils, and hence the read head inductance becomes large and it is difficult to get large reproduced signals.
In cases of Japanese Patent Unexamined Publication Nos.03-063912 and 09-305905, MR sensor elements are provided. However, since the data are recorded with a definite azimuth angle on magnetic mediums, the sensor elements are placed between the two yokes and therefore large reproduced signals cannot be expected.
It is therefore an object of the present invention to provide a thin-film magnetic head whereby recorded data on a magnetic medium with an azimuth angle toward a track width direction can be reproduced with large output signals, and to provide a manufacturing method of the head.
According to the present invention, a thin-film magnetic head includes a substrate with a surface, first and second shield layers formed above the substrate, and a MR sensor element formed between the first and second shield layers. The MR sensor element has a magnetic sensing region formed with a specific slant angle against the surface of the substrate.
The magnetic information recorded by a recording head with the azimuth-angled gap can be sensed with large output signals, because the magnetic sensing region of the MR read element slants against the substrate surface. As a result, both of narrower writing track width and larger output signals can be realized.
It is preferred that the first shield layer is constituted by a single shield layer or independent multi shield layers positioned at the same side of the substrate with respect to the MR sensor element, and that the second shield layer is constituted by a single shield layer or independent multi shield layers positioned at opposite side of the substrate with respect to the MR sensor element.
It is also preferred that each of the first and second shield layers consists of only a magnetic layer or a multi-layered structure formed by alternatively stacking magnetic and non-magnetic layers.
It is preferred that the thin-film magnetic head further includes a recording element formed in integral with the MR sensor element, and that the recording element comprises a writing gap layer which slants against the surface of the substrate so as to become in parallel with the MR sensor element, and a first and a second magnetic pole layers facing each other through the writing gap.
In this case, it is preferred that the thin-film magnetic head further includes auxiliary magnetic pole layers formed in contact with the first and second magnetic pole layers, respectively.
It is also preferred that each of the first and second magnetic pole layers consists of only a magnetic layer or a multi-layered structure formed by alternatively stacking magnetic and non-magnetic layers.
According to the present invention, also a method of manufacturing a thin-film magnetic head, includes the steps of preparing a substrate with a surface, depositing a first shield layer on the surface of the substrate, partially forming a slant surface of the first shield layer by milling the first shield layer through a mask which covers a part of the first shield layer so that the slant surface has a specific angle against the surface of the substrate, forming, on the first shield layer via a shield gap layer, a MR layer with a magnetic sensing region which positions along the slant surface, and forming a second shield layer on the MR layer via a shield gap layer.
It is preferred that the method further includes the steps of planarizing an upper surface of the second shield layer, depositing a first magnetic pole layer above the upper surface of the second shield layer, partially forming a slant surface of the first magnetic pole layer by milling the first magnetic pole layer through a mask which covers a part of the first magnetic pole layer so that the slant surface becomes in parallel with the magnetic sensing region of the MR layer, forming a writing gap layer on the first magnetic pole layer, forming a second magnetic pole layer on the writing gap layer, and planarizing an upper surface of the second magnetic pole layer.
Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.